A traction device communication signal demodulation device and its control method

By designing a demodulation device for traction communication signals that includes a decoding circuit, an amplification circuit, and a controller, the amplification factor is automatically adjusted to adapt to changes in the amplitude of the FSK signal. This solves the demodulation failure problem caused by the insufficient amplitude of the FSK signal and ensures the stability and normal operation of the traction device's communication.

CN117948069BActive Publication Date: 2026-05-26CHINA PETROLEUM & CHEMICAL CORP +3
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Patents(China)
Current Assignee / Owner
CHINA PETROLEUM & CHEMICAL CORP
Filing Date
2023-12-20
Publication Date
2026-05-26

AI Technical Summary

Technical Problem

In the existing technology, the FSK signal amplitude is too small, which causes the traction device communication system to be unable to demodulate, affecting the normal operation of the traction device, and the existing solutions have not effectively solved this problem.

Method used

Design a demodulation device for traction communication signals, including a decoding circuit, an amplification circuit, a demodulator, a second detection circuit, a second microprocessor, and a second controller. The device automatically adjusts the amplification factor to adapt to changes in the amplitude of the FSK signal, ensuring that the demodulator can work normally.

Benefits of technology

It achieves stable communication under different cable and temperature conditions, avoids the demodulator failing to demodulate due to insufficient signal amplitude, and ensures the normal operation of the traction device.

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Abstract

This invention relates to the field of well logging technology, specifically to a demodulation device and control method for a traction device's communication signal. It includes a decoding circuit, an amplifier circuit, a demodulator, a second detection circuit, a second microprocessor, and a second controller. The input terminal of the decoding circuit is connected to the FSK signal output terminal of the surface control system; the output terminal of the decoding circuit is connected to the signal input terminal of the amplifier circuit; the signal output terminal of the amplifier circuit is connected to the signal input terminal of the demodulator; the digital signal output terminal of the demodulator is connected to the traction device's central processing unit; the status feedback signal output terminal of the demodulator is connected to the input terminal of the second detection circuit; the output terminal of the second detection circuit is connected to the input terminal of the second microprocessor; the output terminal of the second microprocessor is connected to the input terminal of the second controller; and the control signal output terminal of the second controller is connected to the control signal input terminal of the amplifier circuit. It can automatically adjust the amplification factor according to the signal strength, ensuring communication stability.
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Description

Technical Field

[0001] This invention relates to the field of well logging technology, specifically to a demodulation device for a traction device communication signal and its control method. Background Technology

[0002] The traction device operation involves the computer sending traction device operation signals, which are modulated into FSK signals by the ground control system and transmitted via cable to the traction device's communication system. The traction device's communication system then demodulates the signals to reconstruct the operation information, ultimately controlling the various actuators of the traction device. However, different cables have different electrical properties, and variations in surface and downhole temperatures often cause the FSK signal amplitude to decrease. This prevents the traction device's communication system from reconstructing the operation information, ultimately hindering the control of the traction device's actuators.

[0003] The demodulation circuit of the traction device consists of a decoding circuit and a demodulator. The FSK signal transmitted from the ground is processed by a detection circuit to eliminate high-frequency interference waves and detect the useful signal of the FSK signal. However, the useful signal usually has a very small amplitude, which the demodulator cannot demodulate. This results in high requirements for the traction device's operating equipment and environment, which is not conducive to the promotion of the traction device.

[0004] Chinese Patent CN107809361B discloses a universal protocol conversion device for downhole instruments, which directly establishes communication between a master control device using Manchester encoding and a downhole measurement device using a 485 / CAN bus. To reduce power consumption, the device can control the power supply to the measurement device as needed, and can also cut off the power supply and communication to the measurement device in case of malfunction or excessive current, ensuring that the malfunction of the measurement device does not affect the entire downhole instrument system. However, this solution does not solve the problem of demodulation failure caused by the often insufficient amplitude of the useful signal.

[0005] Chinese patent CN206972219U discloses a downhole drive execution system with a sleep / wake-up function. Through a multi-channel communication design, it ensures the stability of data communication between the surface control system and intelligent drilling tools, improving the success rate of data decoding. However, it cannot solve the problem that useful signals are often very small in amplitude, making them unmodulatorable by the demodulator.

[0006] The paper "Decoding Method for Surface-to-Downhole Communication Systems During Drilling" published by Zhou Jing and Shang Haiyan studied the decoding method for communication systems, including vibration sensors, decoding circuits, and decoding software. It mainly explained the parameter selection of the decoding circuit and the design process of the decoding software. However, it did not address the demodulation failure problem caused by the often insufficient amplitude of the useful signal. Summary of the Invention

[0007] The purpose of this invention is to address the shortcomings of existing technologies by providing a demodulation device and control method for a traction device communication signal, which can automatically adjust the amplification factor according to the amplitude of the useful FSK signal, thereby avoiding the phenomenon that the demodulator cannot demodulate the FSK signal and ensuring the stability of communication.

[0008] This invention discloses a demodulation device for a traction device communication signal, comprising a decoding circuit, an amplification circuit, a demodulator, a second detection circuit, a second microprocessor, and a second controller. The input terminal of the decoding circuit is connected to the FSK signal output terminal of the ground control system. The output terminal of the decoding circuit is connected to the signal input terminal of the amplification circuit. The signal output terminal of the amplification circuit is connected to the signal input terminal of the demodulator. The digital signal output terminal of the demodulator is connected to the central processing unit of the traction device. The status feedback signal output terminal of the demodulator is connected to the input terminal of the second detection circuit. The output terminal of the second detection circuit is connected to the input terminal of the second microprocessor. The output terminal of the second microprocessor is connected to the input terminal of the second controller. The control signal output terminal of the second controller is connected to the control signal input terminal of the amplification circuit.

[0009] Preferably, the amplification circuit includes amplifier U3, switching transistor Q4, resistors R23, R24, R28, and capacitor C14. The output terminal of the decoding circuit is connected to the drain of the switching transistor Q4 and one end of resistor R24. The other end of resistor R24 ​​is connected to the inverting input terminal of amplifier U3, the source of the switching transistor Q4, and one end of resistor R23. The source of the switching transistor Q4 is connected to the power supply. The non-inverting input terminal of amplifier U3 is connected to one end of resistor R28. The other end of resistor R28 is grounded. The output terminal of amplifier U3 is connected to capacitor C14 and the other end of resistor R23. The other end of capacitor C14 is connected to the input terminal of the demodulator. The gate of the switching transistor Q4 is connected to the control signal output terminal of the second controller.

[0010] Preferably, the amplifier circuit further includes resistors R25, R26, and R27. The source of the switching transistor Q4 is connected to one end of resistor R25, the other end of resistor R25 is connected to one end of resistors R26 and R27, the other end of resistor R26 is connected to the power supply, and the other end of resistor R27 is grounded.

[0011] Preferably, the decoding circuit includes a low-pass filter, an f1 frequency filter, an f2 frequency filter, and an emitter follower. The input of the low-pass filter is connected to the FSK signal output of the ground control system, and its output is connected to the input of the f1 frequency filter. The output of the f1 frequency filter is connected to the input of the f2 frequency filter, and the output of the f2 frequency filter is connected to the input of the emitter follower. The output of the emitter follower is connected to the signal input of the amplifier circuit.

[0012] Preferably, the low-pass filter includes resistors R12 and R13, capacitor C16, and amplifier U2B. The FSK signal output terminal of the ground control system is connected to one end of capacitor C15, the other end of capacitor C15 is connected to one end of resistor R11, the other end of resistor R11 is connected to the inverting input terminal of amplifier U2B, the inverting input terminal of amplifier U2B is connected to one end of capacitor C16 and resistor R12, the other end of capacitor C16 and resistor R12 is connected to the output terminal of amplifier U2B, the non-inverting input terminal of amplifier U2B is connected to one end of resistor R13, the other end of resistor R13 is grounded, the output terminal of amplifier U2B is connected to one end of resistor R14, and the other end of resistor R14 is connected to the input terminal of the f1 frequency filter.

[0013] Preferably, the f1 frequency filter includes resistors R15, R16, R17, R18, capacitor C9, and amplifier U1B. The inverting input terminal of amplifier U1B is connected to one end of capacitor C12 and resistor R17. The other end of capacitor C12 is connected to one end of capacitor C9 and resistor R15. The other end of resistor R15 is grounded. The other end of resistor R17 is connected to one end of resistor R18. The other end of resistor R18 is connected to the output terminal of amplifier U1B, the other end of capacitor C9, and one end of resistor R19. The non-inverting input terminal of amplifier U1B is connected to one end of resistor R16. The other end of resistor R16 is grounded. The other end of resistor R19 is connected to the input terminal of the f2 frequency filter.

[0014] Preferably, the f2 frequency filter includes resistors R21, R22, R20, capacitor C10, and amplifier U1A. The output terminal of the f1 frequency filter is connected to one end of R19, capacitor C11, and capacitor C10. The other end of capacitor C11 is connected to one end of resistor R22 and the inverting input terminal of amplifier U1A. The non-inverting input terminal of amplifier U1A is connected to one end of resistor R21. The other end of resistor R21 is grounded. The other end of resistor R22 is connected to the input terminal of emitter follower. The other end of capacitor C10 is connected to the output terminal of amplifier U1A. The other end of R22 is also connected to the output terminal of amplifier U1A.

[0015] Preferably, the demodulator uses the XR2211M chip.

[0016] The present invention also provides a control method for a traction device communication signal demodulation device, comprising:

[0017] After the traction device starts working, the ground control system sends an FSK signal to the decoding circuit;

[0018] If the second detection circuit does not receive a digital signal within a specified time period, it feeds back an error signal to the second microprocessor.

[0019] The second microprocessor outputs control signals to the second controller;

[0020] The second controller outputs an adjustment signal to the amplifier circuit according to the control signal to adjust the amplification factor of the amplifier circuit until the second detection circuit can receive digital signals within a specified time period.

[0021] A more preferred method for adjusting the amplification factor k of the amplifier circuit is as follows:

[0022] Calculate R based on the set magnification factor k. Q4 Size;

[0023] By adjusting the frequency of the control signal output to the switching transistor Q4, R Q4 The size of R is changed to the required size. Q4 This is the resistance value between the source and drain of the switching transistor Q4.

[0024] Preferably, the magnification factor k is related to R. Q4 The calculation formula is:

[0025]

[0026] in, For resistors R24 and R Q4 The parallel resistance value is R23, where R23 is the resistance value of resistor R23.

[0027] The beneficial effects of this invention are as follows:

[0028] 1. This device includes an amplifier circuit, a second detection circuit, a second microprocessor, and a second controller. The second detection circuit detects the digital signal output. When no digital signal output is detected, decoding failure is promptly identified and fed back to the second microprocessor. The microprocessor then amplifies the signal by adjusting the amplifier's gain, ensuring effective decoding. This device avoids the problem of the demodulator being unable to demodulate the FSK signal due to insufficient amplitude of the useful signal, thus ensuring communication stability.

[0029] 2. The decoding circuit of this device is implemented by connecting a low-pass filter, an f1 frequency filter, an f2 frequency filter, and an emitter follower in sequence, which has a good anti-interference effect and ensures good communication quality.

[0030] 3. This device, through the reasonable setting of the amplification circuit and the formula... The frequency k of the control signal output to the switching transistor Q4 can be calculated quickly and accurately to achieve amplification, which is highly flexible and effective. Attached Figure Description

[0031] Figure 1 This is a circuit diagram of the present invention.

[0032] In the diagram: 20-Decoding circuit, 21-Amplifier circuit, 22-Demodulator, 23-Second detection circuit, 24-Second microprocessor, 25-Second controller. Detailed Implementation

[0033] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0034] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0035] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0036] It should also be understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0037] As used in this application specification and the appended claims, the term "if" may be interpreted, depending on the context, as "when," "once," "in response to determination," or "in response to detection." Similarly, the phrase "if determined" or "if detected [the described condition or event]" may be interpreted, depending on the context, as meaning "once determined," "in response to determination," "once detected [the described condition or event]," or "in response to detection [the described condition or event]."

[0038] References to "one embodiment" or "some embodiments" in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized. "A plurality" means "two or more."

[0039] Example 1

[0040] Figure 1 A preferred embodiment of this application is shown. Figure 1 The diagram shows a circuit schematic of a traction device communication signal demodulation apparatus according to the first embodiment of this application. For ease of explanation, only the parts relevant to this embodiment are shown, and are described in detail below:

[0041] A traction device communication signal demodulation device includes a decoding circuit 20, an amplifier circuit 21, a demodulator 22, a second detection circuit 23, a second microprocessor 24, and a second controller 25. The input terminal of the decoding circuit 20 is connected to the FSK signal output terminal of the ground control system. The output terminal of the decoding circuit 20 is connected to the signal input terminal of the amplifier circuit 21. The signal output terminal of the amplifier circuit 21 is connected to the signal input terminal of the demodulator 22. The digital signal output terminal of the demodulator 22 is connected to the central processing unit of the traction device. The status feedback signal output terminal of the demodulator 22 is connected to the input terminal of the second detection circuit 23. The output terminal of the second detection circuit 23 is connected to the input terminal of the second microprocessor 24. The output terminal of the second microprocessor 24 is connected to the input terminal of the second controller 25. The control signal output terminal of the second controller 25 is connected to the control signal input terminal of the amplifier circuit 21.

[0042] In one embodiment, the amplifier circuit 21 includes an amplifier U3, a switching transistor Q4, resistors R23, R24, R28, and a capacitor C14. The output terminal of the decoding circuit 20 is connected to the drain of the switching transistor Q4 and one end of the resistor R24. The other end of the resistor R24 ​​is connected to the inverting input terminal of the amplifier U3, the source of the switching transistor Q4, and one end of the resistor R23. The source of the switching transistor Q4 is connected to the power supply. The non-inverting input terminal of the amplifier U3 is connected to one end of the resistor R28. The other end of the resistor R28 is grounded. The output terminal of the amplifier U3 is connected to the capacitor C14 and the other end of the resistor R23. The other end of the capacitor C14 is connected to the input terminal of the demodulator 22. The gate of the switching transistor Q4 is connected to the control signal output terminal of the second controller 25.

[0043] In one embodiment, the amplifier circuit 21 further includes resistors R25, R26, and R27. The source of the switching transistor Q4 is connected to one end of resistor R25, the other end of resistor R25 is connected to one end of resistors R26 and R27, the other end of resistor R26 is connected to the power supply, and the other end of resistor R27 is grounded.

[0044] In one embodiment, the decoding circuit 20 includes a low-pass filter, an f1 frequency filter, an f2 frequency filter, and an emitter follower. The input of the low-pass filter is connected to the FSK signal output of the ground control system, and its output is connected to the input of the f1 frequency filter. The output of the f1 frequency filter is connected to the input of the f2 frequency filter, the output of the f2 frequency filter is connected to the input of the emitter follower, and the output of the emitter follower is connected to the signal input of the amplifier circuit 21.

[0045] In one embodiment, the low-pass filter includes resistors R12 and R13, capacitor C16, and amplifier U2B. The FSK signal output terminal of the ground control system is connected to one end of capacitor C15, the other end of capacitor C15 is connected to one end of resistor R11, the other end of resistor R11 is connected to the inverting input terminal of amplifier U2B, the inverting input terminal of amplifier U2B is connected to one end of capacitor C16 and resistor R12, the other end of capacitor C16 and resistor R12 is connected to the output terminal of amplifier U2B, the non-inverting input terminal of amplifier U2B is connected to one end of resistor R13, the other end of resistor R13 is grounded, the output terminal of amplifier U2B is connected to one end of resistor R14, and the other end of resistor R14 is connected to the input terminal of the f1 frequency filter.

[0046] In one embodiment, the f1 frequency filter includes resistors R15, R16, R17, R18, capacitor C9, and amplifier U1B. The inverting input terminal of amplifier U1B is connected to one end of capacitor C12 and resistor R17. The other end of capacitor C12 is connected to one end of capacitor C9 and resistor R15. The other end of resistor R15 is grounded. The other end of resistor R17 is connected to one end of resistor R18. The other end of resistor R18 is connected to the output terminal of amplifier U1B, the other end of capacitor C9, and one end of resistor R19. The non-inverting input terminal of amplifier U1B is connected to one end of resistor R16. The other end of resistor R16 is grounded. The other end of resistor R19 is connected to the input terminal of the f2 frequency filter.

[0047] In one embodiment, the f2 frequency filter includes resistors R21, R22, R20, capacitor C10, and amplifier U1A. The output terminal of the f1 frequency filter is connected to one end of R19, capacitor C11, and capacitor C10. The other end of capacitor C11 is connected to one end of resistor R22 and the inverting input terminal of amplifier U1A. The other end of C10 is connected to the output terminal of amplifier U1A. The other end of R22 is connected to the output terminal of amplifier U1A. The non-inverting input terminal of amplifier U1A is connected to one end of resistor R21. The other end of resistor R21 is grounded. The other end of resistor R22 is connected to the input terminal of the emitter follower.

[0048] In one embodiment, the demodulator 22 uses a chip model XR2211M.

[0049] Example 2

[0050] The present invention also provides a control method for a traction device communication signal demodulation device, comprising:

[0051] After the traction device starts working, the ground control system sends an FSK signal to the decoding circuit 20;

[0052] If the second detection circuit 23 does not receive a digital signal within a specified time period, it will send an error signal back to the second microprocessor 24.

[0053] The second microprocessor 24 outputs control signals to the second controller 25;

[0054] The second controller 25 outputs an adjustment signal to the amplifier circuit 21 according to the control signal to adjust the amplification factor of the amplifier circuit 21 until the second detection circuit 23 receives the digital signal within a specified time period.

[0055] In one embodiment, the method for adjusting the amplification factor k of the amplifier circuit 21 is as follows:

[0056] Calculate R based on the set magnification factor k. Q4 Size;

[0057] By adjusting the frequency of the control signal output to the switching transistor Q4, R Q4 The size of R is changed to the required size. Q4 This is the resistance value between the source and drain of the switching transistor Q4.

[0058] In one embodiment, the magnification factor k and R Q The formula for calculating 4 is:

[0059]

[0060] in, R24 is the parallel resistance of resistors R24 and RQ4, and R23 is the resistance of resistor R23.

[0061] The working principle of this device is as follows:

[0062] The FSK signal transmitted from the ground is sent to terminal 6 of the decoding circuit U2B via cable, capacitor C15, and resistor R11. U2B and surrounding resistors and capacitors (R12, C16, R13) form a low-pass filter to eliminate high-frequency interference waves in the FSK signal, and output a clean FSK signal from terminal 7 of U2B.

[0063] The pure FSK signal is connected to terminal 6 of U1B via resistor R14 and capacitor C12. The f1 frequency filter is formed by U1B and the surrounding resistors and capacitors (R16, R17, R18, R15, C9) to extract the useful signal of the f1 frequency from the pure FSK signal.

[0064] The pure FSK signal is connected to terminals 2 of U1A via U1B, R19, C11, and then the useful signal at frequency f2 in the FSK is extracted by the f2 frequency filter composed of U1A and the surrounding resistors and capacitors (R21, R22, R20, C10).

[0065] The useful signals at frequencies f1 and f2 in the FSK enter the 3 terminal of the emitter follower U2A together. The power of the useful signals at frequencies f1 and f2 is increased by U2A and output from the 1 terminal of U2A.

[0066] The useful signal output from terminal 1 of U2A is connected to terminal 2 of amplifier U3 via R24. Amplified by U3, the useful signal meets the operating requirements of demodulator U4 and is output from terminal 6 of U3. The 12V power supply forms a loop with resistors R26 and R27, outputting a voltage value at one end of R25 to power the source of MOSFET Q4, enabling Q4 to operate when a gate input signal is received.

[0067] The demodulator consists of U4. The useful signal output from pin 6 of U3 is connected to pin 2 of the demodulator via C14. After decoding by U4, a digital signal is output from pin 5 and sent to the traction unit's central processing unit. The traction unit's central processing unit then processes the signal and controls the traction unit to operate other devices. After decoding, pin 5 of U4 is connected to the second detection circuit. The other end of the second detection circuit is connected to the second microprocessor. The other end of the second microprocessor is connected to the second controller. The other end of the second controller is connected to the gate of MOSFET Q4.

[0068] Once the traction device starts operating, the ground will issue commands. If the demodulator cannot decode the useful signal, there will be no digital signal output from pin 5. After 15 seconds without receiving a digital signal, the second detection circuit will output an error signal. This error signal is sent to the second microprocessor, which outputs a control signal. This control signal is connected to the second controller, causing the second controller to output an adjustment signal. The adjustment signal is connected to the gate of the switching transistor and is a sine wave of a certain frequency. By changing the frequency of the sine wave, the resistance between the source and drain of the switching transistor can be changed, thereby changing the amplification factor of U3. The amplification factor of amplifier U3 is the ratio of the parallel resistance of resistor R23 to resistor R24 ​​and the resistance between the source and drain of Q4. The formula is as follows:

[0069]

[0070] It can be seen that by changing R Q4 The resistance can change the amplification factor of amplifier U3. This increases the amplitude of the applied signal and improves the decoding capability of the demodulator. Once the demodulator can decode normally, the central processing unit of the traction device does not receive the error signal from the detection circuit, stops sending control signals, and the controller will automatically stop adjusting the resistance between the source and drain of Q4.

[0071] In the above detailed description, various features are combined together in a single embodiment to simplify this disclosure. This approach to disclosure should not be construed as reflecting an intention that embodiments of the claimed subject matter require more features than are explicitly stated in each claim. Rather, as reflected in the appended claims, the invention is presented with fewer features than all of the features of the single disclosed embodiment. Therefore, the appended claims are hereby explicitly incorporated into the detailed description, wherein each claim stands alone as a preferred embodiment of the invention.

[0072] The disclosed embodiments have been described above to enable any person skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be applied to other embodiments without departing from the spirit and scope of this disclosure. Therefore, this disclosure is not limited to the embodiments given herein, but is consistent with the broadest scope of the principles and novel features disclosed in this application.

[0073] The foregoing description includes examples of one or more embodiments. It is certainly impossible to describe all possible combinations of components or methods in order to describe the above embodiments, but those skilled in the art will recognize that further combinations and arrangements of the various embodiments are possible. Therefore, the embodiments described herein are intended to cover all such changes, modifications, and variations that fall within the scope of the appended claims. Furthermore, the term "comprising" as used in the specification or claims is interpreted in a manner similar to the term "including," as it is used as a conjunction in the claims. Additionally, the use of any term "or" in the specification of the claims is intended to mean "non-exclusive or."

[0074] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A traction device for demodulating communication signals, characterized in that: The system includes a decoding circuit (20), an amplifier circuit (21), a demodulator (22), a second detection circuit (23), a second microprocessor (24), and a second controller (25). The input terminal of the decoding circuit (20) is connected to the FSK signal output terminal of the ground control system. The output terminal of the decoding circuit (20) is connected to the signal input terminal of the amplifier circuit (21). The signal output terminal of the amplifier circuit (21) is connected to the signal input terminal of the demodulator (22). The digital signal output terminal of the demodulator (22) is connected to the central processing unit of the traction device. The status feedback signal output terminal of the demodulator (22) is connected to the input terminal of the second detection circuit (23). The output terminal of the second detection circuit (23) is connected to the input terminal of the second microprocessor (24). The output terminal of the second microprocessor (24) is connected to the input terminal of the second controller (25). The control signal output terminal of the second controller (25) is connected to the control signal input terminal of the amplifier circuit (21). The amplifier circuit (21) includes amplifier U3, switch Q4, resistors R23, R24, R28, and capacitor C14. The output terminal of the decoding circuit (20) is connected to the drain of switch Q4 and one end of resistor R24. The other end of resistor R24 ​​is connected to the inverting input terminal of amplifier U3, the source of switch Q4, and one end of resistor R23. The source of switch Q4 is connected to the power supply. The non-inverting input terminal of amplifier U3 is connected to one end of resistor R28. The other end of resistor R28 is grounded. The output terminal of amplifier U3 is connected to capacitor C14 and the other end of resistor R23. The other end of capacitor C14 is connected to the input terminal of demodulator (22). The gate of switch Q4 is connected to the control signal output terminal of the second controller (25). The decoding circuit (20) includes a low-pass filter, an f1 frequency filter, an f2 frequency filter, and an emitter follower. The input of the low-pass filter is connected to the FSK signal output of the ground control system, and its output is connected to the input of the f1 frequency filter. The output of the f1 frequency filter is connected to the input of the f2 frequency filter, and the output of the f2 frequency filter is connected to the input of the emitter follower. The output of the emitter follower is connected to the signal input of the amplifier circuit (21).

2. The traction device communication signal demodulation device according to claim 1, characterized in that: The amplifier circuit (21) also includes resistors R25, R26, and R27. The source of the switching transistor Q4 is connected to one end of resistor R25. The other end of resistor R25 is connected to one end of resistors R26 and R27. The other end of resistor R26 is connected to the power supply. The other end of resistor R27 is grounded.

3. The traction device communication signal demodulation device according to claim 1, characterized in that: The low-pass filter includes resistors R12 and R13, capacitor C16, and amplifier U2B. The FSK signal output terminal of the ground control system is connected to one end of capacitor C15, the other end of capacitor C15 is connected to one end of resistor R11, the other end of resistor R11 is connected to the inverting input terminal of amplifier U2B, the inverting input terminal of amplifier U2B is connected to one end of capacitor C16 and resistor R12, the other end of capacitor C16 and resistor R12 is connected to the output terminal of amplifier U2B, the non-inverting input terminal of amplifier U2B is connected to one end of resistor R13, the other end of resistor R13 is grounded, the output terminal of amplifier U2B is connected to one end of resistor R14, and the other end of resistor R14 is connected to the input terminal of the f1 frequency filter.

4. The traction device communication signal demodulation device according to claim 1, characterized in that: The f1 frequency filter includes resistors R15, R16, R17, R18, capacitor C9, and amplifier U1B. The inverting input terminal of amplifier U1B is connected to one end of capacitor C12 and resistor R17. The other end of capacitor C12 is connected to one end of capacitor C9 and resistor R15. The other end of resistor R15 is grounded. The other end of resistor R17 is connected to one end of resistor R18. The other end of resistor R18 is connected to the output terminal of amplifier U1B, the other end of capacitor C9, and one end of resistor R19. The non-inverting input terminal of amplifier U1B is connected to one end of resistor R16. The other end of resistor R16 is grounded. The other end of resistor R19 is connected to the input terminal of the f2 frequency filter.

5. The traction device communication signal demodulation device according to claim 1, characterized in that: The f2 frequency filter includes resistors R21, R22, R20, capacitor C10, and amplifier U1A. The output terminal of the f1 frequency filter is connected to one end of resistors R19, C11, and C10. The other end of capacitor C11 is connected to one end of resistor R22 and the inverting input terminal of amplifier U1A. The non-inverting input terminal of amplifier U1A is connected to one end of resistor R21. The other end of resistor R21 is grounded. The other end of resistor R22 is connected to the input terminal of an emitter follower. The other end of capacitor C10 is connected to the output terminal of amplifier U1A. The other end of R22 is also connected to the output terminal of amplifier U1A.

6. The traction device communication signal demodulation device according to claim 1, characterized in that: The demodulator (22) uses a chip model of XR2211M.

7. A control method for a traction device communication signal demodulation device as described in any one of claims 1 to 6, characterized in that, include: After the traction device starts working, the ground control system sends an FSK signal to the decoding circuit (20); If the second detection circuit (23) does not receive a digital signal within a specified time period, it feeds back an error signal to the second microprocessor (24); The second microprocessor (24) outputs control signals to the second controller (25); The second controller (25) outputs an adjustment signal to the amplifier circuit (21) according to the control signal to adjust the amplification factor of the amplifier circuit (21) until the second detection circuit (23) can receive digital signals within a specified time period.

8. The control method as described in claim 7, characterized in that, The method for adjusting the amplification factor k of the amplifier circuit (21) is as follows: Calculate based on the set magnification factor k Size; By adjusting the frequency of the control signal output to the switching transistor Q4, The size is changed to the required size, the This is the resistance value between the source and drain of the switching transistor Q4.

9. The control method as described in claim 8, characterized in that, The magnification factor k and The calculation formula is: ； in, For resistor R24 ​​and The parallel resistance value is R23, where R23 is the resistance value of resistor R23.